In general, a flat panel display device such as a PDP or a LCD is equipped with an antireflection film for minimizing the reflection of light incident from the outside.
As a method for minimizing the reflection of light, there exists a method (anti-glare: AG coating) in which a filler such as an inorganic fine particle is dispersed in a resin and coated onto a substrate film to impart irregularities; a method (anti-reflection: AR coating) of using the interference of light by forming a plurality of layers having different refractive indexes on a substrate film; or a method for mixing them, etc.
Among them, in the case of the AG coating, the absolute amount of the reflected light is equivalent to that of a general hard coating, but a low reflection effect can be obtained by reducing the amount of light entering the eye using light scattering through irregularities. However, since the AG coating has poor screen sharpness due to the surface irregularities, many studies on AR coating have been conducted recently.
As for a film using the AR coating, a multi-layer structure in which a hard coating layer (high refractive index layer), a low reflective coating layer, and the like are laminated on a substrate film has been commercialized. However, the method of forming a plurality of layers as described above has disadvantages in that as the process for forming each layer is performed separately, the interlayer adhesion force (interfacial adhesion) is weak and the scratch resistance is low.
In addition, conventionally, in order to improve the scratch resistance of the low refractive index layer included in the antireflection film, a method of adding various particles in the size of nanometers (for example, particles of silica, alumina, zeolite, etc.) had been mainly attempted. However, when the particles in the size of nanometers were used as described above, there was a limitation in increasing the scratch resistance simultaneously while lowering the reflectivity of the low refractive index layer, and the antifouling property of the surface of the low refractive index layer was greatly reduced due to the nanometer-sized particles.
Accordingly, although many studies have been actively conducted to reduce the absolute reflection amount of light incident from the outside and to improve scratch resistance of the surface as well as to improve the antifouling property, the degree of improvement on the physical properties is insufficient.